The present invention relates to stable, monophasic concentrated compositions containing (per)fluoropolyethers, which are diluted with carriers and excipients in order to be used in the product field for personal care, specifically cosmetic and toilet preparations.
In particular the formulations of the present invention contain functionalized (per)fluoropolyethers, capable to confer improved protective hydro/oil-repellence properties to the formulation itself. The monophasic formulations of the present invention can be used, after dilution, as cosmetic products for the skin and hair-protection towards irritating agents (acids, bases, solvents, detergents) and allergens.
It is well known in the prior art that (per)fluoropoly-ethers due, to their hydro- and oil-repellence and high filmogenic property are very good protective agents towards both hydrophilic and lipophilic irritating agents.
It is also known that it is not possible to use (per)fluoropolyethers as such for the personal care and hygiene and that said compounds must be carried in suitable formulations for topic use in order to advantageously utilize the above mentioned properties of (per)fluoropolyethers.
The (per)fluoropolyether incorporation in polyphase systems in particular under the form of thri-phase emulsions (oil/water/PFPE), used as creams and lotions for skin hydration and protection, is well known. See for example the patents in the name of the Applicant EP 196,904, EP 355,848, EP 390,206. The latter relates to the preparation of concentrated compositions of (per)fluoropolyethers in glycerine in order to facilitate their incorporation in aqueous monophasic systems.
The (per)fluoropolyethers used in these patents have per-fluoroalkyl end groups, which therefore are not reactive end groups.
The drawback of polyphase systems resides in that they require the presence of two essential components: mineral oils (vegetable, animal or synthetic) and emulsifiers (surfactants). The properties of both these components negatively affect the hydro-repellent and/or oil-repellent action of (per)fluoropolyethers having perfluoroalkyl end groups. Therefore in the thri-phase systems of the prior art the hydro- and oil-repellent properties of (per)fluoropolyethers having perfluoroalkyl end groups are reduced.
Also in (per)fluoropolyether systems with glycerine good hydro-repellence values are not obtained.
The thri-phase emulsions are the carrier by which according to the prior art, it is possible to use the above mentioned properties of (per)fluoropolyethers, other systems for formulating compositions having a topic use containing (per)fluoropolyethers, for instance monophase water-based compositions having hydro- and oil-repellent properties, being not available.
The need was felt to have available monophase systems based on perfluoropolyethers having improved hydro- and oil-repellence properties with respect to the known polyphase systems.
The Applicant has surprisingly and unexpectedly found monophase concentrated compositions containing functionalized (per)fluoropolyethers, said compositions dilutable with suitable carriers and excipients, in order to obtain products for the personal care, in particular cosmetic and toilet preparations, said cosmetic preparations having a combination of hydro- and oil-repellence properties clearly superior to those of the above described polyphase systems and even superior to those of the pure (per)fluoropolyethers.
An object of the present invention are therefore concentrated compositions comprising the following components:
A) a (per)fluoropolyether phosphate of general formula:
Rfxe2x80x94[CF2CH2xe2x80x94Oxe2x80x94Lxe2x80x94P(O)(OZ1)(OZ2)]1xe2x80x83xe2x80x83(I)
xe2x80x83wherein 1=1 or 2;
L is a a bivalent linking group, preferably of the (CHR1CHR2O)n type wherein R1, R2 equal to or different from each other are selected from H, CH3; n is an integer in the range 1-50, preferably 1-6;
Z1 equal to or different from Z2 selected from H, alkaline or ammonium cation, di- or tri-alkanolammonium cation wherein alkanol comprises from 1 to 20 C atoms, preferably 1-4 C atoms, di- or tri- or tetra-alkylammonium cation wherein alkyl comprises from 1 to 20 C atoms, preferably 1-4 C atoms, or Rfxe2x80x94CF2CH2xe2x80x94Oxe2x80x94Lxe2x80x94;
Rf is a (per)fluoropolyether chain comprising repeating units selected from one or more of the following ones:
a) xe2x80x94(C3F6O)xe2x80x94;
b) xe2x80x94(CF2CF2O)xe2x80x94;
c) xe2x80x94(CFL0O)xe2x80x94, wherein L0=xe2x80x94F, xe2x80x94CF3;
d) xe2x80x94CF2(CF2)z,CF2Oxe2x80x94, wherein zxe2x80x2 is an integer 1 or 2;
e) xe2x80x94CH2CF2CF2Oxe2x80x94;
when Rf is monofunctional (1=1), an end group is of the perfluoroalkyl type such as for example CF3O, C2F5O, C3F7O; optionally a fluorine atom in the perfluoroalkyl end groups can be substituted by a chlorine or hydrogen atom; examples of these end groups are Cl(C3F6)O, H(C3F6O);
B) a solvent selected from the following ones: linear or branched when possible alcohols, from 2 to 3 carbon atoms and their methyl ethers; linear or branched glycols from 2 to 6 carbon atoms or linear or branched mono alkylethers wherein the alkyl group ranges from 1 to 4 carbon atoms; dimethoxymethane, known as methyl, acetone;
C) water.
The preferred compound of general formula (I) is the one wherein Z1 and Z2 are different from Rfxe2x80x94CF2CH2xe2x80x94Oxe2x80x94Lxe2x80x94; preferably Z1=Z2=H and in formula (I) 1=2.
In particular, Rf is of perfluoropolyether type and it has preferably one of the following structures:
xe2x80x94(CF2O)axe2x80x94(CF2CF2O)bxe2x80x94xe2x80x83xe2x80x831)
with b/a in the range 0.3-10, extremes included, a being an integer different from 0;
xe2x80x94(CF2xe2x80x94(CF2)zxe2x80x2xe2x80x94CF2O)bxe2x80x2xe2x80x94xe2x80x83xe2x80x832)
wherein zxe2x80x2 is an integer equal to 1 or 2;
xe2x80x94(C3F6O)rxe2x80x94(C2F4O)bxe2x80x94(CFL0O)txe2x80x94,xe2x80x83xe2x80x833)
with r/b=0.5-2.0(r+b)/t=10-30, b and t being integers different from 0;
xe2x80x94(OC3F6)rxe2x80x94(CFL0O)txe2x80x94OCF2xe2x80x94Rxe2x80x2fxe2x80x94CF2Oxe2x80x94(C3F6O)rxe2x80x94(CFL0O)txe2x80x94xe2x80x83xe2x80x834)
xe2x80x94(CF2CF2CH2O)qxe2x80x2xe2x80x94Rxe2x80x2fxe2x80x94Oxe2x80x94(CH2CF2CF2O)qxe2x80x2xe2x80x94xe2x80x83xe2x80x835)
wherein:
Rxe2x80x2f is a fluoroalkylene group from 1 to 4 carbon atoms;
L0 is selected between F, CF3;
xe2x80x94(C3F6O)rxe2x80x94OCF2xe2x80x94Rxe2x80x2fxe2x80x94CF2Oxe2x80x94(C3F6O)rxe2x80x94xe2x80x83xe2x80x836)
wherein in said formulas:
xe2x80x94(C3F6O)xe2x80x94 can represent units of formula:
xe2x80x94(CF(CF3)CF2O)xe2x80x94 and/or xe2x80x94(CF2xe2x80x94CF(CF3)O)xe2x80x94
a, b, bxe2x80x2, qxe2x80x2, r, t, are integers, whose sum is such that Rf has number average molecular weight {overscore (M)}n values in the range of about 300 and about 5,000, and preferably in the range 800-2,500.
The preferred (per)fluoropolyether chain Rf is selected from the following structures:
from the bifunctional ones (1=2):
xe2x80x94(CF2O)axe2x80x94(CF2CF2O)bxe2x80x94;
xe2x80x94(C3F6O)rxe2x80x94(C2F4O)bxe2x80x94(CFL0O)txe2x80x94;
from the monofunctional ones (1=1):
(C3F6O)rxe2x80x94(CFL0O)txe2x80x94;
wherein L0 and the a,b,r,t indexes have the above mentioned value, still more preferably xe2x80x94(CF2O)axe2x80x94(CF2CF2O)bxe2x80x94.
The compounds of formula (I) preferably used according to the present invention are those having L=(CH2xe2x80x94CH2O)n with n=1-3; Z1 equal to or different from Z2 is selected from H, NH4, or an alkaline metal cation; 1=2.
The compounds of general formula (I), having the following formulas, are still more preferred:
xe2x80x83CF3xe2x80x94O(CF2CF(CF3)O)r(CF2O)axe2x80x94CF2xe2x80x94CH2(OCH2CH2)nOxe2x80x94PO(OH)2xe2x80x83xe2x80x83(II)
wherein r/a=0.5-2.0 and n=1-2;
xe2x80x94CF2xe2x80x94O(CF2CF2O)b(CF2O)axe2x80x94CF2xe2x80x94[CH2xe2x80x94(OCH2CH2)nOxe2x80x94PO(OH)2]2xe2x80x83xe2x80x83(III)
wherein b/a=0.5-3.0 and n=1-2;
wherein a, b and r have the above mentioned meaning.
The component B) is preferably selected from: ethanol, ethylene glycol, isopropanol, propanol, acetone, methoxyethanol, propylene glycol, propan-1,2-diol, dimethoxy methane, methoxy-isopropanol, diethylene glycol, butan-1,4-diol, diethylenglycol monoethylenether, pentan-1,2-diol, diethylenglycol monoethylether, dipropylenglycol, dipropylenglycol monomethylether, dipropylenglycol monoethylether; still more preferably: ethanol, isopropanol and propylene glycol.
In the concentrated composition of the invention the amounts of each of the components A), B) and C) can range from 0.01% to 70% by weight of the composition, preferably from 20% to 40% by weight, the sum of A)+B)+C) being equal to 100% by weight of the composition.
Still more preferably the concentrated composition contains component A) in a percentage by weight in the range 20%-40%, component B) in the range 30-70% and water component C) in the minimum amount required to obtain a clear solution (the compound of formula (I) as such is insoluble in water), and component C) is generally in the range 5-30% by weight.
The composition of the invention appears as a monophase clear solution, stable in the time in environmental conditions at temperatures in the range from 10xc2x0 C. to 35xc2x0 C. also for long periods (6 months or more) of shelf storage.
Another object of the present invention is a process for preparing said concentrated compositions comprising the following steps:
solubilization or dispersion with partial solubilization of a (per)fluoropolyether phosphate component A) in component B) at room temperature under mild stirring;
addition under stirring, to the previous mixture of water component C) initially dropwise, so that component A) is not separated, by dispersing the drop so that the initial appearance of the solution is recovered before adding the subsequent ones, the water aliquots can be increased until the addition is completed, lastly obtaining a clear solution.
Surprisingly while the (per)fluoropolyether phosphate as such in unsoluble in water the mixture of the perfluoropolyether phosphate with component B) is instead dilutable with water to form, as said, a clear solution.
The added water is preferably at a temperature in the range 50xc2x0 C.-60xc2x0 C.
Another object of the present invention is the use of the concentrated compositions of the invention for the preparation of cosmetic compositions under the form of solutions, gels, emulsions, pastes and areosols or serviettes impregnated with said cosmetic compositions for the skin protection against irritating agents, for the hair protection and treatment, for the protection against sun radiations, for detergency, as deodorants, after-shaves, disinfectants for external use, make-up compositions and for the nail-varnish removal.
To formulate the cosmetic compositions, the concentrated compositions of the present invention are diluted with the necessary solvents and excipients so that the final percentage by weight of the (per)fluoropolyether phosphate is in the range 0.01-10%, preferably 0.5-5%.
The concentrated composition can for example be diluted to form a homogeneous solution. In this case the dilution solvent is for example selected from water, acetone, linear or branched alcohols from 2 to 3 carbon atoms and their corresponding methyl ethers; linear or branched glycols from 2 to 6 carbon atoms and their corresponding monoalkylethers wherein the linear or branched ether alkyl group has a number of carbon atoms from 1 to 4; dimethoxymethane.
Preferably the diluent is water or it is formed by mixtures of water with one or more of the other above mentioned solvents or diluents.
To said final solution the excipients well known to the skilled man, such as perfumes, dyes, etc., can be added.
The concentrated composition can also be directly added to an already formulated hydrophilic gel, obtaining protective gels. The hydrophilic gelling agents can for example be selected from polysaccharides, such as cellulose derivatives, xanthan rubber, carruba rubber and alginates; acrylic derivatives, such as carbomer, glyceropolyacrylates and polymethacrylates; mineral and synthetic silicates; inorganic salts such as sodium chloride or magnesium sulphate.
Said protective gels can comprise other ingredients or excipients well known to the skilled man, such as pigments, sun filters, emollient oils (including non functionalized perfluoropolyethers), surfactants.
The concentrated composition of the present invention can be added to emulsions of the oil/water, or water/oil type or to gel emulsions based on acrylic polymer emulsifiers such as Pemulen(copyright) TR-1 or Pemulen(copyright) TR-2, obtaining stable emulsions. Said emulsions are considered stable since no separation of phases both after conditioning for 60 days in stove at the temperature of 40xc2x0 C., and after centrifugation at 4,000 rpm for 10 minutes, occurs.
Other cosmetic compositions can be prepared by formulating the concentrated composition object of the present invention with suitable carriers and excipients well known to the skilled man in order to obtain soaps, syndet (synthetic soaps) or mixtures thereof; shampoos, preferably containing non ionic and anionic surfactants; tooth pastes.
For the evaluation of the protective hydro and oil-repellent activity, absorption tests have been carried out on filter paper treated with the concentrated composition of the present invention and of a cosmetic gel formulation obtained by said concentrated composition. See the Examples.
The (per)fluoropolyethers of general formula (I) are obtainable by the well known processes of the prior art, see for example the following patents herein incorporated by reference: U.S. Pat. Nos. 3,665,041, 2,242,218, 3,715,378, and EP 239,123. The functionalized fluoropolyethers having an hydroxyl termination are obtained for example according to EP 148,482, U.S. Pat. No. 3,810,874.
The preparation of the monofunctional (per)fluoropolyether phosphates of general formula (I) wherein Rf has a perfluoroalkyl end group can be carried out by reacting the corresponding monohydroxy-terminated (per)fluoroalkylenoxides with POCl3. A molar ratio POCl3/hydroxy-terminated compound in the range 2/1-10/1, preferably 6/1-8/1 is used. The reaction is carried out by slowly dropping the monohydroxy-terminated (per)fluoropolyether in POCl3, at a temperature in the range 50xc2x0-100xc2x0 C., preferably 70xc2x0-80xc2x0 C., by eliminating the HCl vapours in a KOH trap. The POCl3 excess is removed by distillation while the formed adduct is hydrolized by H2O. The hydrolyzed adduct is further reacted for example with an equimolar amount of hydroxy-terminated (per)fluoropolyether to form the ester.
The separation of the obtained product is carried out by extraction with a suitable organic solvent, such as for example ethyl acetate. From the organic phase the compound of formula (I) is separated according to known techniques, for example by the solvent evaporation.
The preparation of bifunctional (per)fluoropolyether phosphates (in this case Rf of formula (I) has no perfluoroalkyl end groups) can be carried out by reacting the corresponding di-hydroxy-terminated (per)fluoroalkylenoxides with POCl3. A molar ratio POCl3/di-hydroxy-terminated compound in the range 4/1-20/1, preferably 12/1-16/1, is used. The reaction is carried out by slowly dropping the hydroxy-terminated compound in POCl3, at a temperature in the range 50xc2x0-100xc2x0 C., preferably 70xc2x0-80xc2x0 C., by eliminating the HCl vapours in a KOH trap. The POCl3 excess is removed by distillation while the formed adduct is hydrolized by H2O. The separation of the product is carried out by extraction with an organic solvent, such as for example ethyl acetate. From the organic phase the product is separated according to known techniques, for example by solvent evaporation.